Methods for processing audio signals are for example known from the following documents, to which reference will be made to in this document and which are incorporated by reference herein in their entirety:    [1] M. Schroeder, B. Atal, “Code-excited linear prediction (CELP): High -quality speech at very low bit rates”, Proc.    ICASSP'85, pp. 937-940, 1985.    [2] T. Painter, “Perceptual Coding of Digital Audio”, Proc. Of IEEE, vol. 88. no. 4, 2000.    [3] European Telecomm. Standards Institute, “Adaptive Multi-Rate (AMR) speech transcoding” ETSI Rec. GSM 06.90    (1998).